Unveiling inflammatory biomarkers in multibacillary leprosy: the role of lymphocyte-platelet ratio in predicting leprosy reactions.

ABSTRACT

Leprosy is a neglected contagious disease that causes physical disability and episodes of inflammation, called leprosy reactions. There are currently no consolidated laboratory markers that can predict or confirm the diagnosis of leprosy reactions, negatively impacting the progression of the disease. The aim of this study was to analyze the behavior of inflammatory biomarkers in a population of patients with multibacillary leprosy. This prospective study in a northeastern capital involved 67 new cases of multibacillary leprosy, assessing inflammatory biomarkers at diagnosis. Histopathology, qPCR, slit skin smear microscopy, and laboratory tests, including CRP-albumin, neutrophil-lymphocyte, lymphocyte-monocyte, platelet-lymphocyte ratios, and systemic immune-inflammation index, were conducted. Statistical analysis utilized Stata version 16.0®, employing Chi-square, Kruskal-Wallis, and Poisson regression (5% significance). The population, mainly young brown men with low socioeconomic status, borderline leprosy, and and degree of physical disability one, saw 19.4% experiencing leprosy reactions. Standard multibacillary multidrug therapy was administered to all. Ratios and index values exceeding medians were prevalent (46.3-47.8%). Assessing biological markers against leprosy reactions revealed a positive relation between reactions and lymphocyte-platelet ratio (p = 0.05) and a positive trend with the systemic immune-inflammation index (p = 0.06). Patients with reactions were 1.3 times more likely to exhibit an elevated lymphocyte-platelet ratio. The lymphocyte-platelet ratio emerged as a potential indicator for recognizing leprosy reactions. Further research is essential to validate these findings, aiming for earlier detection of leprosy reactions.